DESCRIPTION: The objective of Core B1 is to provide developmentally based patient evaluations for persons enrolled in MRRC studies. These evaluations will be performed at the Meyer Center for Developmental Pediatrics, a unit operated collaboratively by Baylor College of Medicine and Texas Children's Hospital. This core will provide routine service in cases where billing is not feasible and more specialized evaluations are required for investigative purposes. The five major areas of investigation to which this core has contributed include studies of developmental outcomes following high-risk birth, the effects of CMV, measurement of mediation efficacy in treatment for AIDS, neurodevelopmental effects on dietary intake of polyunsaturated fatty acids, and clarification of the phenotypes of various genetic disorders. Eleven projects will use this core, including a number of studies of genetic syndromes, CMV, head injury, and AIDS. The cytogenetics core laboratory will perform classical cytogenetics on patients recruited in the research projects of MRRC investigators, and FSH mapping of genes or DNA markers. A total of 12 projects will require the services of this core facility. The Biochemical Genetics Laboratory provides testing for patients with inborn errors of metabolism. A small proportion of patients with mental retardation have single gene metabolic disorders that can be diagnosed by screening markers such as amino acids, organic acids, sugars, and mucopolysaccharides, etc. A second function of this core is to help investigators involved in mouse gene disruption by performing measurements of biochemical markers such as amino acids and organic acids as well as enzymatic assays. A third function is to perform follow up testing in patients with urea cycle disorders who would be receiving gene therapy. Hence, this is a metabolic markers screening and enzyme analysis laboratory which will be available for investigators of the MRCC.